New potato breeding strategy

We have developed a potato breeding strategy at the Institute which avoids the common but ineffective practice of intense early-generation visual selection between seedlings in a glasshouse and spaced plants at a seed site (Bradshaw et al., 1998, 2003).

• Pair crosses made as usual, but then different.
• Progeny tests (seedling tests for disease and pest resistance and visual assessment of tubers; and tuber tests for fry colour and further visual assessment) used to discard whole progenies before starting conventional within-progeny selection at unreplicated small-plot stage.
• Clones visually selected from best progenies for use as parents in the next cycle of crosses (full-sib family selection on three year cycle) whilst also multiplied for assessment of yield and quality.
• Midparent values, as well as progeny tests, used to select between resultant crosses.
• Material from other breeding programmes included in parental assessments and progeny tests and used in next cycle of crosses if superior.
• Number of clones available for selecting new cultivars is increased by sowing more true seed of best progenies but without selection until small-plot stage.
• New programme used to combine quantitative resistances to late blight and the white potato cyst nematode with acceptable tuber yields and quality, a combination of traits not available in commonly grown European cultivars.
• Parental material made available from programme for use in commercially funded breeding programmes leading to new cultivars.
• Diallele analysis confirmed presence of large amounts of additive genetic variance for foliage blight, tuber blight, and nematode resistance as well as for breeders’ preference and fry colour (Bradshaw et al., 1995, 2000); and predicted good progress which is being achieved in practice.

References

Bradshaw, J.E., Stewart, H.E., Wastie, R.L., Dale, M.F.B. and Phillips, M.S. 1995. Use of seedling progeny tests for genetical studies as part of a potato (Solanum tuberosum subsp. tuberosum) breeding programme. Theoretical and Applied Genetics 90, 899 - 905.

Bradshaw, J.E., Dale, M.F.B., Swan, G.E.L., Todd, D. and Wilson, R.N. 1998. Early-generation selection between and within pair crosses in a potato (Solanum tuberosum subsp. tuberosum) breeding programme. Theoretical and Applied Genetics 97, 1331 - 1339.

Bradshaw, J.E., Todd, D. and Wilson, R.N. 2000. Use of tuber progeny tests for genetical studies as part of a potato (Solanum tuberosum subsp. tuberosum) breeding programme. Theoretical and Applied Genetics 100, 772 - 781.

Bradshaw, J.E., Dale, M.F.B. and Mackay, G.R. 2003. Use of mid-parent values and progeny tests to increase the efficiency of potato breeding for combined processing quality and disease and pest resistance. Theoretical and Applied Genetics 107, 36 - 42.